Surface cleaning apparatus

ABSTRACT

A surface cleaning apparatus comprises at least one cyclone and at least one dirt collection chamber. The at least one cyclone has a cyclone air inlet, a cyclone air outlet and a removably mounted shroud surrounding the cyclone air outlet. The at least one dirt collection chamber comprises an opening and an openable door covering the opening. The shroud is removable through the opening when the door is open.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date of CanadianPatent Application. No. 2658046, filed Mar. 11, 2009, entitled SURFACECLEANING APPARATUS

FIELD

The specification relates to surface cleaning apparatus, andparticularly, to cyclonic surface cleaning apparatus. In a particularlypreferred embodiment, the specification relates to cyclonic hand vacuumcleaners having removably mounted screen.

INTRODUCTION

The following is not an admission that anything discussed below is priorart or part of the common general knowledge of persons skilled in theart.

Cyclonic separators, including those used in vacuum cleaners are knownin the art. Typically, a cyclonic separator has an inlet for fluid (air,liquid or and air and liquid mix) to be treated and an outlet fortreated fluid. Dirt may be collected either in the cyclone chamberitself (e.g. in the bottom) or in a collection chamber in fluidcommunication with the cyclone separator. Various such constructions areknown in the art.

Typically, a screen or shroud is provided in a cyclonechamber-surrounding the air outlet. The purpose of the screen is toretain hair and the like in the cyclone chamber. Accordingly, materialmay build up on a screen or shroud, requiring the screen or shroud to becleaned. The shroud may be cleaned while mounted to a vacuum cleaner.For example, in U.S. Pat. No. 4,853,111, a vacuum cleaner having ssecond cyclone nested within an outer cyclone is disclosed. The outercyclone casing was removable. Once the outer cyclone casing was removed,then the shroud was exposed, permitting the shroud to be cleaned.US2007/0209334 disclosed a design wherein a screen is configured so asto be removable through or with the fluid outlet of a cyclone.

Cyclonic hand vacuum cleaners have also been developed. These vacuumcleaners have typically used similar operating principles as full sizecyclonic vacuum cleaners. See for example PCT publication WO2008/009890; PCT publication WO 2008/009888; PCT publication WO2008/009883; and U.S. Pat. No. 7,370,387.

SUMMARY

The following introduction is provided to introduce the reader to themore detailed discussion to follow. The introduction is not intended tolimit or define the claims.

According to one broad aspect, a surface cleaning apparatus is providedwherein a screen of shroud (hereinafter “shroud”) is positioned at leastpartially internal of a cyclone chamber such that the air will passthrough the shroud as it exits the cyclone chamber. The cyclone has anassociated dirt collection chamber that is openable to empty dirtcollected therein. When opened, the shroud, which is removably mountedin the cyclone, may be removed. The dirt collection chamber may be inthe bottom of the cyclone chamber. In such a case, a cyclone casing mayhave an openable bottom door. The door may be positioned to face thecyclone outlet. When the door is opened, a user may remove the screenfor cleaning. Alternately, the dirt collection chamber may be externalof the cyclone chamber. For example, the cyclone chamber may have a dirtoutlet at an end of the cyclone opposed to the air outlet. The dirtcollection chamber may have an openable bottom door. The door may bepositioned to face the cyclone outlet. When the door is opened, a usermay remove the screen for cleaning.

Accordingly, a cyclone unit may have only one openable portion that isused to remove accumulated dirt and also to remove a screen forcleaning. It will be appreciated that the reference to “bottom” is aconvenience. In use, a cyclone may be oriented in various directions.

In one embodiment, a surface cleaning apparatus has a front end, a rearend and an air flow passage extending from a dirty air inlet to a cleanair outlet. A first cyclone unit is positioned in the air flow passage.The first cyclone unit comprises at least one cyclone and at least onedirt collection chamber. The at least one cyclone has a cyclone airinlet, a cyclone air outlet, and a removably mounted shroud surroundingthe cyclone air outlet. The at least one dirt collection chambercomprises an opening and an openable door covering the opening. Theshroud is removable through the opening when the door is open. A suctionmotor is positioned in the air flow passage.

In some example, the dirt collection chamber is external to the cyclone.

In some examples, the at least one cyclone further comprises a dirtoutlet, the opening is provided in the at least one dirt collectionchamber and the openable door is mounted facing the dirt outlet

The surface cleaning apparatus may be a hand vacuum cleaner.

In some examples, a vortex finder is provided in the cyclone, and theshroud comprises a screen surrounding the vortex finder.

In some examples, the door is removable. The door may be openable whenthe first cyclone unit is mounted to the surface cleaning apparatusand/or when the first cyclone unit is removed from the surface cleaningapparatus.

In some examples, the at least one cyclone is positioned interior of theat least one dirt collection chamber. The at least one cyclone may bedefined by a cyclone casing that is sized to permit a user to insert ahand in an annular portion of the cyclone chamber positioned between theshroud and the cyclone casing.

In some examples, the surface cleaning apparatus comprises a hand vacuumcleaner and the door is positioned at the front end.

In some examples, the surface cleaning apparatus comprises a hand vacuumcleaner and the first cyclone unit is positioned forward of the suctionmotor.

In some examples, the surface cleaning apparatus comprises a hand vacuumcleaner, the at least one cyclone has a cyclone front end, and a cyclonerear end, and the cyclone air inlet and the cyclone air outlet are atthe same end. The cyclone air inlet and the cyclone air outlet may be atthe cyclone rear end.

In some examples, a separation plate is mounted in facing relation tothe dirt outlet, preferably at an end opposed to the air outlet.

In some examples, the surface cleaning apparatus comprises a hand vacuumcleaner, the cyclone has a separation plate that is mounted in facingrelation to the dirt outlet, the dirt outlet is positioned at thecyclone front end, and the cyclone front end is positioned at the frontend of the hand vacuum cleaner. The separation plate may be mounted tothe door.

In some examples, the dirt collection chamber is removable from thesurface cleaning apparatus as a sealed unit for emptying. The dirtcollection chamber may be removable from the surface cleaning apparatuswith the first cyclone unit.

In some examples, the shroud has a dirt outlet end and the dirt outletend is positioned proximate the dirt outlet.

In some examples, the first cyclone unit has a single cyclone and asingle dirt collection chamber.

In some examples, the surface cleaning apparatus further comprises asuction motor housing. The suction motor may be positioned in thesuction motor housing and the first cyclone unit may be removablymounted to the suction motor housing.

In some examples, the surface cleaning apparatus further comprises asecond cyclone unit downstream from the first cyclone unit.

It will be appreciated that a surface cleaning apparatus may incorporateone or more of the features of each of these examples.

DRAWINGS

In the detailed description, reference will be made to the followingdrawings, in which:

FIG. 1 is a side plan view of an example of a hand vacuum cleaner;

FIG. 2 is a top plan view of the hand vacuum cleaner of FIG. 1;

FIG. 3 is a front plan view of the hand vacuum cleaner of FIG. 1;

FIG. 4 is a partially exploded rear perspective view of the hand vacuumcleaner of FIG. 1;

FIG. 5A is a front perspective view of the hand vacuum cleaner of FIG.1, showing a door in an open configuration;

FIG. 5B is a front perspective view of the hand vacuum cleaner of FIG.1, showing a door removed from the hand vacuum cleaner;

FIG. 6 is a cross section taken along line 6-6 in FIG. 2;

FIG. 7A is a bottom perspective view of the hand vacuum cleaner of FIG.1; and,

FIG. 7B is a rear perspective view of the hand-vacuum cleaner of FIG. 1,showing the cyclone unit removed from the hand vacuum cleaner.

DESCRIPTION OF VARIOUS EXAMPLES

Various apparatuses or methods will be described below to provide anexample of each claimed invention. No example described below limits anyclaimed invention and any claimed invention may cover processes orapparatuses that are not described below. The claimed inventions are notlimited to apparatuses or processes having all of the features of anyone apparatus or process described below or to features common tomultiple or all of the apparatuses described below. It is possible thatan apparatus or process described below is not an embodiment of anyclaimed invention.

In the drawings attached hereto, the surface cleaning apparatus isexemplified as used in a hand vacuum cleaner that uses a cyclone. Itwill be appreciated that the vacuum cleaner 100 may be of various types(e.g., an upright vacuum cleaner, a canister vacuum cleaner, anextractor, etc.) and configurations (e.g., different positioning andorientation of the cyclone unit and the suction motor and differingcyclone units that may comprise one or more cyclones and one or morefilters).

Referring to FIGS. 1 to 7B, a first example of a surface cleaningapparatus 100 is shown. The surface cleaning apparatus 100 (alsoreferred to herein as vacuum cleaner or cleaner 100) is a hand vacuumcleaner 100, and is movable along a surface to be cleaned by grippingand maneuvering handle 102. The vacuum cleaner 100 includes an upperportion 104, a lower portion 106, a front end 108, and a rear end 110.In the example shown, handle 102 is provided at the upper portion 104.In alternate examples, handle 102 may be provided elsewhere on thevacuum cleaner 100, for example at the rear end 110, and may be of anydesign.

In the example shown, the vacuum cleaner 100 comprises a nozzle 112 anda first cyclone unit 114, which together preferably form a surfacecleaning head 116 of the vacuum cleaner 100. In the example shown, thesurface cleaning head 116 is preferably provided at the front end 108 ofthe vacuum cleaner 100.

Nozzle 112 engages a surface to be cleaned, and comprises a dirty airinlet 118, through which dirty air is drawn into the vacuum cleaner 100.An airflow passage extends from the dirty air inlet 118 to a clean airoutlet 120 of the cleaner 100. In the example shown, clean air outlet120 is at the rear end 110 of the cleaner 100.

Cyclone unit 114 is provided in the airflow passage, downstream of thedirty air inlet 118. The cyclone unit 114 comprises at least one cycloneand at least one dirt collection chamber. In the example shown, thecyclone unit 114 comprises one cyclone 122, and one dirt collectionchamber 124, which are integrally formed. In alternate examples, thecyclone unit 114 may include more than one cyclonic stage, wherein eachcyclonic stage comprises one or more cyclones and one or more dirtchambers. Accordingly, the cyclones may be arranged in parallel and/orin sequence. Further, in alternate examples, the cyclone 122 and dirtcollection chamber 124 may be separately formed.

In the example shown, the nozzle 112 is positioned at the lower portion106 of the vacuum cleaner 100. Preferably, as exemplified, nozzle 112 ispositioned at the bottom of the vacuum cleaner 100, and, preferably,beneath the cyclone unit 114. However, it will be appreciated thatnozzle 112 may be connected to the cyclone unit or dirt collectionchamber at alternate locations.

Preferably, as exemplified, nozzle 112 may be on lower surface 157 ofcyclone unit 114 and may share a wall with the cyclone unit 114. Forexample in a particularly preferred design, the upper wall of the nozzlemay be a lower wall of the cyclone unit 114. As shown in FIG. 6, dirtchamber 124 surrounds the lower portion of cyclone 122. Accordingly, theupper wall of nozzle 112 may be part of the lower wall of the dirtchamber. It will be appreciated that if dirt chamber 124 does not extendaround the lower portion of cyclone 122, then the upper wall of nozzle112 may be part of a lower wall of cyclone 122.

Preferably, in the example shown, the nozzle 112 is fixedly positionedat the lower portion 106 of the vacuum cleaner 100. That is, the nozzle112 is not movable (e.g., rotatable) with respect to the remainder ofthe vacuum cleaner 100, and is fixed at the lower portion 106 of thevacuum cleaner 100.

As shown in FIGS. 3 and 6, nozzle 112 has a width WN, and cyclone unit114 has a width WC. In the example shown, WN, and WC are about the same.An advantage of this design is that the nozzle 112 may have a cleaningpath that is essentially as wide as the hand vacuum itself.

Preferably, nozzle 112 comprises an airflow chamber 136 wherein at leasta portion, and preferably a majority, of the lower surface of thechamber 136 is open. In an alternate design, nozzle 112 may be anenclosed passage and accordingly may have a lower wall that the closeslower end. Accordingly, nozzle 112 may be of various designs and may bean open sided passage or a closed passage. In either embodiment, it willbe appreciated that nozzle 112 may be mounted or provided on cycloneunit 114 and as exemplified on a lower portion of the dirt collectionchamber so as to be removable with the dirt collection chamber.

An open sided nozzle design is exemplified in FIG. 7A wherein nozzle 112comprises an upper nozzle wall 126. In the example shown, the uppernozzle wall 126 comprises a portion 119 of a wall 115 of the cycloneunit. Accordingly, nozzle 112 is integral with cyclone unit 114.

Preferably, one or more depending walls 128 extend downwardly from theupper nozzle wall 126. The depending wall 128 is preferably generallyU-shaped. In one embodiment, depending wall is provided rearward ofopening 138. In other embodiments, depending walls may alternately or inaddition be provided on the lateral sides of opening 138. It ispreferred that depending walls are provided on each lateral side ofopening 138 and rearward thereof. Further, depending walls 128 mayextend a substantial distance to the front end 108 and, preferably,essentially all the way to front end 108. The depending wall 128 may becontinuous to define a single wall as shown, or may be discontinuous.The depending wall 128 is preferably rigid (e.g., integrally molded withcyclone unit 114). However, they may be flexible (e.g., bristles orrubber) or moveably mounted to cyclone unit 114 (e.g., hingedlymounted).

Preferably, the lower end 132 of depending wall 128 is spaced above thesurface being cleaned when the hand vacuum cleaner is placed on asurface to be cleaned. As exemplified in FIG. 6, when vacuum cleaner 100is placed on a floor F, lower end 132 of depending wall 128 may bespaced a distance H above the floor. Preferably distance H is from 0.01to 0.175 inches, more preferably from 0.04 to 0.08 inches.

The height of the depending wall (between upper nozzle wall 126 andlower end 132) may vary. In some examples, the depending wall may have aheight of between about 0.05 and about 0.875 inches, preferably betweenabout 0.125 and about 0.6 inches, and more preferably between about 0.2and about 0.4 inches. The height of depending wall may vary but ispreferably constant.

As exemplified, the open end of the U-shape defines an open side 130 ofthe nozzle 114, and forms the dirty air inlet 118 of the cleaner 100. Inthe example shown, the open side 130 is provided at the front of thenozzle 114. In use, when optional wheels 135 are in contact with asurface, the open side 130 sits above and is adjacent a surface to becleaned (e.g. floor F). As mentioned hereinabove, preferably, lower end132 of depending walls 128 is spaced above floor F. Accordingly, someair may enter nozzle 114 by passing underneath depending wall 132. Insuch a case, the primary air entry to nozzle 114 is via open side 130 sothat dirty air inlet 118 is the primary air inlet, with a secondary airinlet being under depending wall 128.

In the example shown, the lower end 132 of the depending wall 128defines an open lower end 134 of the nozzle 114. The open lower end 134preferably extends to the front 108 of the cleaner 100, and merges withthe open side 130. In use, the exemplified nozzle has an open lower end134 that faces a surface to be cleaned.

In the example shown, a plurality of wheels 135 are mounted to thedepending wall 128, and extend lower than the lower end 132 of thedepending wall 128. Accordingly, in use, when wheels 135 are in contactwith a surface, the lower end 132 of the depending wall 128 is spacedfrom the surface to be cleaned, and the space between the lower end ofthe depending wall 128 and the surface to be cleaned form the secondarydirty air inlet to the vacuum cleaner 100. It will be appreciated thatwheels 135 are optional. Preferably, wheels 135 are positioned exteriorto the airflow path through nozzle 112, e.g., laterally outwardly fromdepending wall 128. Preferably a pair of front wheels 135 are provided.Preferably, the wheels are located adjacent front 108. Optionally, oneor more rear wheels 108 may be provided. In an alternate embodiment, nowheels may be provided.

The upper nozzle wall 126, depending wall 128, and open lower end 134 ofthe nozzle 112 define the open sided airflow chamber 136 of the nozzle.In use, when wheels 135 are in contact with a horizontal surface, thenozzle 112 and the airflow chamber 136 extend generally horizontally,and preferably linearly along a nozzle axis 113 (see FIG. 7A).

An opening 138 may be provided in the upper nozzle wall 126, and is incommunication with the airflow chamber 136. Opening 138 may be of anysize and configuration and at various locations in upper nozzle wall126. In use, when wheels 135 are in contact with a surface, the opening138 faces a surface to be cleaned, air enters the dirty air inlet 118,passes horizontally through the airflow chamber 136, and passes into theopening 138. Opening 138 is in communication with a cyclone inletpassage 139, which is in communication with a cyclone air inlet 140 ofcyclone 122.

Cyclone 122 may of any configuration and orientation. Preferably,cyclone 122 comprises a cyclone casing 142, which in the example shown,is cylindrical. The cyclone chamber is located inside cyclone casing142. The cyclone 122 extends along an axis 123, which, in the exampleshown, is preferably parallel to the nozzle axis, and preferably extendsgenerally horizontally when cleaner 100 is in use and wheels 135 areseated on a surface. Cyclone 122 has a first end 196, which in theexample shown is the front of the cyclone, and a second end 198, whichin the example shown is a rear 198 of the cyclone. The cyclone air inletand air outlet may be at various locations and configurations.

As exemplified, the cyclone air inlet 140 may be defined by an aperturein the cyclone casing 142, and may be at the rear 198 of the cyclone122. As can be seen in FIG. 5, the inlet passage 139 is configured suchthat air enters the cyclone 122 in a tangential flow path, e.g., passage139 may be arcuate. The air travels in a cyclonic path in the cyclone,and dirt in the air is separated from the air. The air exits the cyclonevia air outlet 145. Outlet 145 may be in rear wall 179 of the cycloneunit 114. Accordingly, cyclone inlet 140 and outlet 145 may be at thesame end of the cyclone 122. Preferably, the cyclone air inlet and thecyclone air outlet are at the same end of the cyclone 122 and the dirtoutlet is at an opposed end.

In the exemplified embodiment, a vortex finder 144 is provided in thecyclone, upstream from and in communication with the dirt outlet 145. Asexemplified, the vortex finder is a cylindrical conduit, having an inlet176 facing the outlet 145.

Preferably, a shroud 182 surrounds the cyclone air outlet. The shroud182 serves to prevent elongate material and larger, lighter dirt frompassing through dirt outlet 145. As exemplified, the shroud 182surrounds the vortex finder 144. Preferably, as shown, the shroud 182comprises a plate 174 at a first end 189 thereof. The plate 174 isspaced from and facing the inlet 176 to vortex finder 144. Legs 178extend from plate 174, along vortex finder 144. A ring 185 is at asecond end 191 of the shroud 182, which is positioned proximate the dirtoutlet 145. The second end 191 may also be referred to herein as the airoutlet end 191. The ring 185 is integral with legs 178 and surroundsvortex finder 144. The ring and legs provide a mount for plate 174. Ascreen 183 extends from plate 174, around legs 178, to ring 185.Accordingly, the screen 183 is positioned in the air flow path of airexiting the cyclone chamber and entering the vortex finder 144. It willbe appreciated that in alternate embodiments, the shroud may be anyother suitable configuration. For example, a plate 174 need not beprovided. End 189 may be covered by screen 183. Screen 183 may be madeof a wire mesh. Alternately, shroud 182 may be a molded plastic coveringvortex finder 144 and may have a plurality of apertures therein.

The dirt collection chamber may be internal or external to the cyclonechamber. Preferably, as exemplified, the dirt collection chamber 124 isexternal. That is, the cyclone 122 may be positioned interior of oradjacent the dirt collection chamber 124. The dirt collection chambermay be in communication with the cyclone chamber by any means known inthe art. Accordingly, one or more dirt outlets may be provided.

In the exemplified embodiment, the cyclone chamber is positionedinternal of the dirt collection chamber 124. Accordingly, the cyclonechamber is provided with a dirt outlet 146. Dirt outlet 146 may be ofvarious designs provided access is provided to access shroud 182.Preferably as exemplified, dirt outlet 146 faces the air outlet andaccording in the exemplified design, is at the front 196 of the cyclone122, and further, is at the front end 108 of the cleaner 100.

Preferably, as in the example shown, dirt collection chamber 124comprises two portions. A first portion 148 is provided immediatelyadjacent the dirt outlet 146, and is at the front end 108 of the cleaner100. A second portion 150 is concentric with the cyclone 122. A lowerportion 152 of the second portion 150 is below the cyclone. Asexemplified, nozzle 112 may be positioned below first portion 148, andlower portion 152. Accordingly, dirt chamber 124 may comprise an annularchamber surrounding the cyclone 122.

A separation plate 154 may be provided in the dirt collection chamber124, adjacent the dirt outlet 146, and in facing relation to the dirtoutlet. The separation plate 154 aids in preventing dirt in dirtcollection chamber 124 from re-entering cyclone 122. Preferably, plate154 is spaced from dirt outlet 146. Plate 154 may be mounted by anymeans to any component in cyclone unit 114. As exemplified, theseparation plate is preferably mounted to a front wall 158, which is atthe front 108 of the cleaner 100 and preferably faces the dirt outlet146. The separation plate 154 is mounted to front wall 158 by an arm156, which preferably extends from front wall 158.

Cyclone unit 114 may be emptied through an opening 187, which is coveredby a removable door. The door may be removable while the cyclone unit ismounted to the vacuum cleaner. Alternately, or in addition, the door maybe removable when the cyclone unit has been removed from the vacuumcleaner. The door may be removably secured to the cyclone unit oranother portion of vacuum cleaner 100 by any means. For example, one ormore latches 159 may secure the door in position. Alternately, the doormay be opened, e.g., pivoted open, and then be removable. For example,as exemplified in FIGS. 4 to 5B, front wall 158 covers opening 187, andis pivotally mounted to the cyclone unit wall 115 at pivots 177. Frontwall 158 serves as an openable door 158 of the dirt chamber 124, suchthat dirt collection chamber 124 is openable, and dirt collectionchamber 124 may be emptied through opening 187. As shown in FIG. 6,pivots 177 are separable into two portions. As exemplified, pivots 177have an upper recess 199 that is semi circular in transverse section anddefine an axis in which an axle 197 provided on front wall 158 mayrotate. When front wall 158 is pivoted to the open position, the axles197 may be lifted off the pivots 177 thereby permitting front wall 158to be lifted off the vacuum cleaner.

The removable door is preferably provided at the front of the vacuumcleaner, or on a surface that does not face another component of thevacuum cleaner. Accordingly, the dirt collection chamber is openableboth when the dirt collection chamber is mounted to the hand vacuumcleaner, or when it is removed. When door 158 is pivoted away or removedfrom the remainder of the cyclone unit 114, separation plate 154 and arm156 also pivot away from the remainder of the cyclone unit.

The rear portion of the dirt collection chamber 124 may be closed bywall 179.

Preferably, as shown in FIGS. 4 to 5B, the shroud 182 is removablymounted to the cyclone 122, and is removable through opening 187 whenthe door 158 is open. The shroud 182 may be removably mounted in anymanner, to any portion of the cleaner 100. For example, the ring 185 ofthe shroud 182 may frictionally mount to the vortex finder 144.Alternately, the ring 185 of the shroud may be mountable to wall 179 orvortex finder 144 by a bayonet mount. Alternately, the ring 185 of theshroud may be provided with screw threads that screw into screw threadson wall 179 or vortex finder 144 or magnets may be used to secure theshroud in position.

In an alternate embodiment, dirt collection chamber may be a portion ofthe cyclone (i.e. internal of the casing defining the cyclone chamber).In such a case a plate 154 may be provided inside the cyclone chamber todefine the dirt collection chamber 124. In any event, a door may beprovided so as to empty the cyclone and the shroud may be removablethrough the door.

Preferably, the cyclone casing 142 is sized to permit a user to insert ahand in the annular portion of cyclone chamber 122 positioned betweenthe shroud 182 and the cyclone casing 142. Accordingly, the user maygrip the shroud 182 to remove the shroud 182 from the cyclone 122.Preferably, a portion of shroud 182 is located adjacent dirt outlet 146such that a user may grasp the shroud without having to insert much oftheir hand into the cyclone casing.

The clean air exiting cyclone 122 passes through outlet 145 of vortexfinder 144, exits surface cleaning head 116, and passes into the cleanerbody 160. As the example shown, a cleaner body 160 may be positionedrearward of the surface cleaning head 116. The cleaner body may comprisea suction motor housing 168, which houses an optional pre-motor filter162, a suction motor 164 and may house an optional post-motor filter166.

In the example shown, suction motor housing 168 further houses apre-motor filter 162. Pre-motor filter 162 is provided in the airflowpath adjacent and downstream of the vortex finder 144, and facing theoutlet 145. Pre-motor filter 162 serves to remove remaining particulatematter from air exiting the cyclone 122, and may be any type of filter,such as a foam filter. One or more filters may be used. In theexemplified embodiments, the vacuum cleaner has a linear configuration.If the vacuum cleaner is of a non-linear configuration, then pre-motorfilter 162 need not be located adjacent vortex finder 144.

Suction motor 104 is provided in the airflow path adjacent anddownstream of the pre-motor filter 162. The suction motor 164 may be anytype of suction motor. The suction motor draws air into the dirty airinlet 118 of the cleaner 100, through the airflow path past the suctionmotor 164, and out of the clean air outlet 120. The suction motor 164has a motor axis 165. In the example shown, the motor axis 165 and thecyclone axis 123 preferably extend in the same direction and arepreferably generally parallel. In the exemplified embodiments, thevacuum cleaner has a linear configuration. If the vacuum cleaner is of anon-linear configuration, then motor 164 need not be located adjacentpre-motor filter 162.

The cleaner body 160 further comprises a post-motor filter housing 170.A post motor filter 166 is provided in the post-motor filter housing170. The post-motor filter 166 is provided in the airflow pathdownstream of, and preferably adjacent, the suction motor 164. Postmotor filter 166 serves to remove remaining particulate matter from airexiting the cleaner 100. Post-motor filter 166 may be any type offilter, such as a HEPA filter. If the vacuum cleaner is of a non-linearconfiguration, then post motor filter 166 need not be located adjacentsuction motor 164.

Clean air outlet 120 is provided downstream of post-motor filter 166.Clean air outlet 120 may comprise a plurality of apertures formed inhousing 170.

Referring to FIG. 7B, the dirt collection chamber 124 is preferablyremovable from the hand vacuum cleaner 100 and, more preferably as asealed unit for emptying. In the example shown, the cyclone unit 114comprises the dirt collection chamber 124. Accordingly, the cyclone unit114 is removable from the hand vacuum cleaner, and the dirt collectionchamber 124 is removably from the hand vacuum cleaner 100 with thecyclone unit 114. As the cyclone unit 114 is integral with nozzle 112and airflow chamber 136, nozzle 112 and airflow chamber 136 areremovable from the cleaner 100 with cyclone unit 114. In the exemplifiedembodiment, the cyclone unit 114 is removably mounted to the suctionmotor housing 168.

As can be seen in FIG. 7B, when the cyclone unit 114 is removed from thehand vacuum cleaner, and particularly from motor housing 168, it issealed, except for the fluid flow passages leading to and from the firstcyclone unit (i.e. opening 138 and outlet 145). That is, wall 179 andfront wall 158 seal the cyclone unit 114. In order to empty the dirtcollection chamber 124, the front wall 158 may be removed, and the dirtmay be emptied from dirt chamber 124.

As exemplified, in order to remove cyclone unit 114 from the surfacecleaning apparatus, the cyclone unit comprises a first mounting member173, and the suction motor housing 168 has a second mounting member 175.The first 173 and second 175 mounting members are releasably engageablewith each other. In the example shown, the first 173 and second 175mounting members comprise a bayonet mount. In alternate examples, thefirst and second mounting members may be another type of mountingmember, such as mating screw threads, magnets, mechanical members suchas screws or any other type of mounting members.

One or more rear wheels 180 may be mounted to housing 161, preferably atlower portion 106, and may be used in conjunction with wheels 135.Preferably, a single rear wheel 180 is provided. Preferably, rear wheel180 is located on a centre line of the vacuum cleaner and rearward ofthe depending wall 128.

In an alternate embodiment (not shown), the surface cleaning apparatusmay further comprise a second cyclone unit. The second cyclone unit maycomprise one or more cyclones. The cyclones may be arranged in series orin parallel. The second cyclone unit may be mounted in motor housing168, or in a separate housing. The second cyclone unit may be removablymounted to the first cyclone unit 114, or to the motor housing 168.

1. A surface cleaning apparatus comprising: (a) a front end and a rearend: (b) an air flow passage extending from a dirty air inlet to a cleanair outlet; (c) a first cyclone unit positioned in the air flow passage,the first cyclone unit comprising at least one cyclone and at least onedirt collection chamber, the at least one cyclone having a cyclone airinlet, a cyclone air outlet, and a removably mounted shroud surroundingthe cyclone air outlet, the at least one dirt collection chambercomprising an opening and an openable door mounted in the opening, theshroud is removable through the opening when the door is open; and, (d)a suction motor positioned in the air flow passage.
 2. The surfacecleaning apparatus of claim 1 wherein the dirt collection chamber isexternal to the cyclone.
 3. The surface cleaning apparatus of claim 2wherein the at least one cyclone further comprises a dirt outlet, theopening is provided in the at least one dirt collection chamber and theopenable door is mounted facing the dirt outlet.
 4. The surface cleaningapparatus of claim wherein a vortex finder is provided in the cyclone,and the shroud comprises a screen surrounding the vortex finder.
 5. Thesurface cleaning apparatus of claim 1 wherein the deer is removable. 6.The surface cleaning apparatus of claim 1 wherein the door is openablewhen the first cyclone unit is mounted to the surface cleaning apparatus7. The surface cleaning apparatus of claim 1 wherein the at least onecyclone is positioned interior of the at least one dirt collectionchamber and the at least one cyclone is defined by a cyclone casing thatis sized to permit a user to insert a hand in an annular portion of thecyclone chamber positioned between the shroud and the cyclone casing. 8.The surface cleaning apparatus of claim 1 wherein the surface cleaningapparatus comprises a hand vacuum cleaner and the door is positioned atthe front end.
 9. The surface cleaning apparatus of claim 1 wherein thesurface cleaning apparatus comprises a hand vacuum cleaner and the firstcyclone unit is positioned forward of the suction motor.
 10. The surfacecleaning apparatus of claim 1 wherein the surface cleaning apparatuscomprises a hand vacuum cleaner, the at least one cyclone has a cyclonefront end, and a cyclone rear end, and the cyclone air inlet and thecyclone air outlet are at the same end.
 11. The surface cleaningapparatus of claim 10 wherein the cyclone air inlet and the cyclone airoutlet are at the cyclone rear end.
 12. The surface cleaning apparatusof claim 1 wherein the at least one cyclone has a first end, and asecond end, and the cyclone air inlet and the cyclone air outlet are atthe same end.
 13. The surface cleaning apparatus of claim 10 wherein aseparation plate is mounted in facing relation to the dirt outlet. 14.The surface cleaning apparatus of claim 10 wherein the surface cleaningapparatus comprises a hand vacuum cleaner, the cyclone has a separationplate that is mounted in facing relation to the dirt outlet and the dirtoutlet is positioned at the cyclone front end and the cyclone front endis positioned at the front end of the hand vacuum cleaner.
 15. Thesurface cleaning apparatus of claim 13 wherein the separation plate ismounted to the door.
 16. The surface cleaning apparatus of claim 1wherein the dirt collection chamber is removable from the surfacecleaning apparatus as a sealed unit for emptying.
 17. The surfacecleaning apparatus of claim 1 wherein the dirt collection chamber isremovable from the surface cleaning apparatus with the first cycloneunit.
 18. The surface cleaning apparatus of claim 1 wherein the shroudhas a dirt outlet end and the dirt outlet end is positioned proximatethe dirt outlet.
 19. The surface cleaning apparatus of claim 1 whereinthe first cyclone unit has a single cyclone and a single dirt collectionchamber.
 20. The surface cleaning apparatus of claim 1 furthercomprising a suction motor housing, the suction motor is positioned inthe suction motor housing and the first cyclone unit is removablymounted to the suction motor housing.
 21. The surface cleaning apparatusof claim 1 further comprising a second cyclone unit downstream from thefirst cyclone unit.
 22. The surface cleaning apparatus of claim 1wherein the surface cleaning apparatus is a hand vacuum cleaner.